Convert-Si project aims to develop optimized processes for a total conversion of industrial plants by-products into value-added products. Main innovative contribution is related to the introduction of a (pre)treatment step based on new microbial products: non-catalytic small proteins from cerato-platanin family (CP), which weaken (ligno)cellulose structure, metabolites from silicon solubilizing microorganisms (SiM) and super-active ligno-cellulolytic enzymes. Convert-all project integrated approach is intended to close a biomimetic industrial symbiosis. The by-products of one conversion process represent raw material for other conversion steps. Convert-Si proposed cascade process is applied to two value-added chains: cereal husks and/or bran, fruit/grape pomace. From these the following ingredients are recovered: anti-oxidant polyphenols and/or feruloylated oligosaccharides, useful for new cosmetics and dietary supplement products; essential oil terpenes and (brassino)steroids, trapped and/or bounded by/to lignocellulose network, with plant growth stimulating and/or insects repellent activities; biosilica (BSi); fermentable carbohydrates, recalcitrant lignin. BSi, fermentable carbohydrates and recalcitrant lignin are converted into mesoporous silica nanoparticles, value added fermented food / feed (probiotics) supplements and, respectively, substrate for plant biostimulants formulation. Mesoporous silica nanoparticles are used for the “ smart”, controlled released formulation of the recovered polyphenols, essential oils, and (brassino)steroids. Recalcitrant lignin, together with the biomass of CP producing microorganisms and, respectively, SiM will be used for the production of a complex plant biostimulant. Safety and efficacy of biosilica nano-particles and “smart” formulated phytoextracts will be tested by state of the art high through-output cell assay.